001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.model;
018
019 import java.util.concurrent.ExecutorService;
020 import java.util.concurrent.ScheduledExecutorService;
021 import javax.xml.bind.annotation.XmlAccessType;
022 import javax.xml.bind.annotation.XmlAccessorType;
023 import javax.xml.bind.annotation.XmlAttribute;
024 import javax.xml.bind.annotation.XmlRootElement;
025 import javax.xml.bind.annotation.XmlTransient;
026
027 import org.apache.camel.Expression;
028 import org.apache.camel.Processor;
029 import org.apache.camel.builder.ExpressionBuilder;
030 import org.apache.camel.model.language.ExpressionDefinition;
031 import org.apache.camel.processor.Throttler;
032 import org.apache.camel.spi.RouteContext;
033 import org.apache.camel.util.ObjectHelper;
034
035 /**
036 * Represents an XML <throttle/> element
037 *
038 * @version
039 */
040 @XmlRootElement(name = "throttle")
041 @XmlAccessorType(XmlAccessType.FIELD)
042 public class ThrottleDefinition extends ExpressionNode implements ExecutorServiceAwareDefinition<ThrottleDefinition> {
043 // TODO: Camel 3.0 Should not support outputs
044
045 @XmlTransient
046 private ExecutorService executorService;
047 @XmlAttribute
048 private String executorServiceRef;
049 @XmlAttribute
050 private Long timePeriodMillis;
051 @XmlAttribute
052 private Boolean asyncDelayed;
053 @XmlAttribute
054 private Boolean callerRunsWhenRejected;
055
056 public ThrottleDefinition() {
057 }
058
059 public ThrottleDefinition(Expression maximumRequestsPerPeriod) {
060 super(maximumRequestsPerPeriod);
061 }
062
063 @Override
064 public String toString() {
065 return "Throttle[" + description() + " -> " + getOutputs() + "]";
066 }
067
068 protected String description() {
069 return getExpression() + " request per " + getTimePeriodMillis() + " millis";
070 }
071
072 @Override
073 public String getShortName() {
074 return "throttle";
075 }
076
077 @Override
078 public String getLabel() {
079 return "throttle[" + description() + "]";
080 }
081
082 @Override
083 public Processor createProcessor(RouteContext routeContext) throws Exception {
084 Processor childProcessor = this.createChildProcessor(routeContext, true);
085
086 boolean shutdownThreadPool = ProcessorDefinitionHelper.willCreateNewThreadPool(routeContext, this, isAsyncDelayed());
087 ScheduledExecutorService threadPool = ProcessorDefinitionHelper.getConfiguredScheduledExecutorService(routeContext, "Throttle", this, isAsyncDelayed());
088
089 // should be default 1000 millis
090 long period = getTimePeriodMillis() != null ? getTimePeriodMillis() : 1000L;
091
092 // max requests per period is mandatory
093 Expression maxRequestsExpression = createMaxRequestsPerPeriodExpression(routeContext);
094 if (maxRequestsExpression == null) {
095 throw new IllegalArgumentException("MaxRequestsPerPeriod expression must be provided on " + this);
096 }
097
098 Throttler answer = new Throttler(routeContext.getCamelContext(), childProcessor, maxRequestsExpression, period, threadPool, shutdownThreadPool);
099
100 if (getAsyncDelayed() != null) {
101 answer.setAsyncDelayed(getAsyncDelayed());
102 }
103
104 if (getCallerRunsWhenRejected() == null) {
105 // should be true by default
106 answer.setCallerRunsWhenRejected(true);
107 } else {
108 answer.setCallerRunsWhenRejected(getCallerRunsWhenRejected());
109 }
110 return answer;
111 }
112
113 private Expression createMaxRequestsPerPeriodExpression(RouteContext routeContext) {
114 if (getExpression() != null) {
115 if (ObjectHelper.isNotEmpty(getExpression().getExpression()) || getExpression().getExpressionValue() != null) {
116 return getExpression().createExpression(routeContext);
117 }
118 }
119 return null;
120 }
121
122 // Fluent API
123 // -------------------------------------------------------------------------
124 /**
125 * Sets the time period during which the maximum request count is valid for
126 *
127 * @param timePeriodMillis period in millis
128 * @return the builder
129 */
130 public ThrottleDefinition timePeriodMillis(long timePeriodMillis) {
131 setTimePeriodMillis(timePeriodMillis);
132 return this;
133 }
134
135 /**
136 * Sets the time period during which the maximum request count per period
137 *
138 * @param maximumRequestsPerPeriod the maximum request count number per time period
139 * @return the builder
140 */
141 public ThrottleDefinition maximumRequestsPerPeriod(Long maximumRequestsPerPeriod) {
142 setExpression(new ExpressionDefinition(ExpressionBuilder.constantExpression(maximumRequestsPerPeriod)));
143 return this;
144 }
145
146 /**
147 * Whether or not the caller should run the task when it was rejected by the thread pool.
148 * <p/>
149 * Is by default <tt>true</tt>
150 *
151 * @param callerRunsWhenRejected whether or not the caller should run
152 * @return the builder
153 */
154 public ThrottleDefinition callerRunsWhenRejected(boolean callerRunsWhenRejected) {
155 setCallerRunsWhenRejected(callerRunsWhenRejected);
156 return this;
157 }
158
159 /**
160 * Enables asynchronous delay which means the thread will <b>noy</b> block while delaying.
161 *
162 * @return the builder
163 */
164 public ThrottleDefinition asyncDelayed() {
165 setAsyncDelayed(true);
166 return this;
167 }
168
169 public ThrottleDefinition executorService(ExecutorService executorService) {
170 setExecutorService(executorService);
171 return this;
172 }
173
174 public ThrottleDefinition executorServiceRef(String executorServiceRef) {
175 setExecutorServiceRef(executorServiceRef);
176 return this;
177 }
178
179 // Properties
180 // -------------------------------------------------------------------------
181
182 public Long getTimePeriodMillis() {
183 return timePeriodMillis;
184 }
185
186 public void setTimePeriodMillis(Long timePeriodMillis) {
187 this.timePeriodMillis = timePeriodMillis;
188 }
189
190 public Boolean getAsyncDelayed() {
191 return asyncDelayed;
192 }
193
194 public void setAsyncDelayed(Boolean asyncDelayed) {
195 this.asyncDelayed = asyncDelayed;
196 }
197
198 public boolean isAsyncDelayed() {
199 return asyncDelayed != null && asyncDelayed;
200 }
201
202 public Boolean getCallerRunsWhenRejected() {
203 return callerRunsWhenRejected;
204 }
205
206 public void setCallerRunsWhenRejected(Boolean callerRunsWhenRejected) {
207 this.callerRunsWhenRejected = callerRunsWhenRejected;
208 }
209
210 public ExecutorService getExecutorService() {
211 return executorService;
212 }
213
214 public void setExecutorService(ExecutorService executorService) {
215 this.executorService = executorService;
216 }
217
218 public String getExecutorServiceRef() {
219 return executorServiceRef;
220 }
221
222 public void setExecutorServiceRef(String executorServiceRef) {
223 this.executorServiceRef = executorServiceRef;
224 }
225 }